git worktree parallel branches

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Imagine you're a busy bee, flitting from flower to flower, collecting nectar for your hive. You need to inspect multiple flowers at once, without having to move from one to another. This is similar to the problem developers face when working on multiple branches simultaneously. Git worktree comes to our rescue, allowing us to have multiple branches checked out in parallel, without having to re-clone the repository.

The Technique

Git worktree is a feature that allows you to check out multiple branches of a repository at the same time, without having to create separate clones of the repository for each branch. This is particularly useful when working on review or testing multiple features concurrently.

To use git worktree, you need to have Git version 2.13 or later installed on your system. Here's how you can enable it:

git add submodule --path=$(pwd) git-worktree

Next, create a new branch where you want to work and then use the git worktree command to check out that branch in parallel with your current branch.

git checkout -b feature/new-feature origin/master
git worktree add feature/new-feature origin/feature/new-feature

This will check out the feature/new-feature branch, which is a parallel copy of the original repository. Now you can make changes to this branch independently without affecting your current branch.

Example 1: Reviewing Multiple Pull Requests

Let's say we have two pull requests open for review, PR-1234 and PR-5678. We want to review both pull requests simultaneously. Here's how we can use git worktree:

git checkout main
git branch -b pr-review origin/main
git worktree add pr-review-origin/feature/pr-1234 origin/feature/pr-1234

Now you have two parallel branches, pr-review and pr-review-feature/pr-1234, where you can review both pull requests simultaneously.

Example 2: Testing Multiple Features

Suppose we're working on a project with multiple features that need to be tested. We want to test each feature independently without affecting the others. Here's how git worktree can help:

git checkout main
git branch -b feature-testing origin/main
git worktree add feature-testing-origin/feature/new-feature-1 origin/feature/new-feature-1
git worktree add feature-testing-origin/feature/new-feature-2 origin/feature/new-feature-2

Now you have two parallel branches, feature-testing and its sub-branches, where you can test each feature independently.

Example 3: Debugging a Complex Issue

Imagine we're debugging a complex issue that requires us to switch between multiple commits. Git worktree allows us to check out specific commits in parallel, making it easier to debug the issue:

git checkout main
git branch -b debug-issue origin/main
git worktree add debug-issue-commit-a commit_a_hash
git worktree add debug-issue-commit-b commit_b_hash

Now you have two parallel branches, debug-issue and its sub-branches, where you can debug the issue by switching between specific commits.

When NOT to Use It

While git worktree is a powerful tool for working with multiple branches in parallel, there are some scenarios where it might not be the best choice:

• Large repositories: If your repository is extremely large, creating multiple parallel branches using git worktree can lead to performance issues.
• Complex workflows: In cases where you have complex workflows or dependencies between branches, git worktree might introduce more complexity than necessary.

Related Apiary Lessons

If you're new to Git or want to learn more about working with branches, check out these related Apiary lessons:

• Git Branching
• Git Merge vs Rebase
• Git Stash vs Worktree

Conclusion

In conclusion, git worktree is a powerful feature that allows you to have multiple branches checked out in parallel without having to re-clone the repository. Whether you're reviewing pull requests, testing features, or debugging complex issues, this technique can help streamline your workflow and improve productivity.

As the great beekeeper once said, "A busy hive is a happy hive." With git worktree, you'll be able to manage multiple branches like a pro, making your development process more efficient and enjoyable.